The proposed project involves ongoing research using synthetically prepared protein-acidic phospholipid analogues for studying dental calculus calcification. The analogues are based upon the finding that hydroxyapatite formation in microbial, dental calculi and certain vertebrate calcifications is initiated by proteolipids, nonpolar protein-acidic phospholipid aggregates. The synthetic analogues are providing a valuable tool for investigating both the mechanism of proteolipid calcification and its inhibition. In the case of the latter, an assay method has been developed in which potential anti-calculus agents can be evaluated within 3-4 days.